“…Electric fields are used to reverse the direction of travel of the ions halfway through their flight. As ions with a velocity higher than intended for their m/z penetrate deeper into the reflectron, the reflection time is increased, so the otherwise shortening of their time of flight is largely cancelled out, providing the electric fields are tuned correctly (Weickhardt et al, 1996). An advantage of this over PSPF is that providing it is correctly tuned, the increase in resolution benefits the ions of all m/z.…”